1. Field of the Invention
The present invention relates to a metabolite of a xanthine Phosphodiesterase type 5 (“PDE 5”) inhibitor useful for treatment of erectile dysfunction, and derivatives, formulations and processes related thereto.
2. Background
U.S. patent application Ser. No. 09/940,760, incorporated herein by reference, teaches a class of xanthine PDE 5 inhibitor compounds useful for the treatment of impotence. U.S. Pat. Nos. 5,939,419 and 5,393,755, both of which are incorporated herein by reference, disclose polycyclic guanine PDE 5 derivatives that are useful for the treatment of cardiovascular and pulmonary disorders.
Certain xanthine/guanine PDE 5 inhibitors have been found to be useful for treating cardiovascular and pulmonary disorders, while others have been found useful for treating urological disorders, including male erectile dysfunction. Generally, it has been suggested that PDE 5 inhibitors may be useful for treating physiological disorders, symptoms or diseases that include urogenital, cardiovascular, cerebrovascular and peripheral vascular disorders, angina pectoris, hypertension, restenosis post angioplasty, endarterectomy, stent introduction, cerebral stroke, respiratory tract disorders such as allergic conditions associated with atopy, pulmonary hypertension, ischemic heart disorders, impaired glucose tolerance, diabetes and its related complications, insulin resistance syndrome, hyperglycemia, polycystic ovarian syndrome, glomerular disorders, renal insufficiency, nephritis, tubular interstitial disorders, autoimmune disorders, glaucoma, intestinal motility, cachexia or cancer.
In the treatment of erectile dysfunction, it is believed that PDE 5 inhibitors are beneficial therapeutic agents because they elevate cGMP levels in the human body. This action facilitates corpus cavernosum smooth muscle relaxation, which provides an increased flow of blood therein and results in an erection. This makes PDE 5 inhibitors especially useful for treating impotence and other types of diseases that are affected by cGMP levels.
In U.S. patent application Ser. No. 09/940,760, Compound 114 in Table II, herein identified as Compound A, was disclosed as having PDE 5 inhibitory activity.
